In one known light-emitting element, a wavelength conversion member prepared by dispersing fluorescent material particles in a resin typified by epoxy, silicone, etc. is disposed so as to be in contact with, for example, a blue LED element. In recent years, there are an increasing number of applications that use, instead of LEDs, laser diodes (LDs) whose energy efficiency is high and which can easily adapt to a reduction in size and an increase in output power.
A laser irradiates a narrow area with high energy light. When a resin is locally irradiated with laser light, the irradiated portion is burnt. One solution proposed to address this issue is to irradiate a ring-shaped wavelength conversion member with laser light while the wavelength conversion member is rotated at high speed, in order to prevent burning (Patent Document 1).
However, with the above solution, apparatuses and devices are increased in size and complexity, and strong restrictions are imposed on the system. In other proposals, inorganic binders are used instead of the resin used to form the above wavelength conversion member, and wavelength conversion members composed only of inorganic materials are used (Patent Documents 2 to 7).